DNS Security Best Practices: Protecting Your Domain from Attacks
Learn the essential DNS security measures every domain owner should implement — including DNSSEC, registrar locks, monitoring, and email authentication — to protect against unauthorized transfers and impersonation.
Why DNS Security Matters
DNS is the foundation of your entire internet presence. If your DNS is compromised, unauthorized entities can redirect your website traffic to different servers, intercept email sent to your domain, or impact your online identity — all while your actual servers remain untouched. DNS security failures have caused some of the most damaging incidents in internet history.
The Most Common DNS Attacks
DNS Hijacking: An attacker gains control of your domain's DNS records — either by compromising your registrar account or DNS provider account — and changes your records to point to malicious servers. Visitors to your website are transparently redirected to attackers' servers.
Cache Poisoning: Attackers inject fake DNS records into a resolver's cache, causing users querying that resolver to be directed to malicious IPs instead of your legitimate servers. DNSSEC is specifically designed to prevent this attack.
Subdomain Takeover: When DNS records point to resources (like S3 buckets or cloud services) that have been deprovisioned, attackers can claim those resources and take over the subdomain. This is called "dangling DNS."
Domain Expiration Hijacking: Domains that expire are released back to the public. Attackers monitor expiring domains and register valuable ones immediately after they drop.
Essential DNS Security Controls
1. Enable DNSSEC
DNSSEC (DNS Security Extensions) adds cryptographic signatures to DNS records, allowing resolvers to verify that records are authentic and were not tampered with in transit. DNSSEC specifically prevents cache poisoning attacks.
Most major DNS providers (Cloudflare, AWS Route 53, Google Cloud DNS) support DNSSEC and make it easy to enable. Your registrar must also support DS record submission to complete the chain of trust.
2. Use a Reputable DNS Provider with Strong Security
Your DNS provider's security is your security. Evaluate DNS providers based on:
- Support for two-factor authentication (2FA) on control panel access
- Change logging and alerting (notifications when records are modified)
- DNSSEC support
- Anycast infrastructure (resilience against DDoS)
- Service level agreement and uptime history
3. Apply Registrar Locks
Domain registrar locks prevent unauthorized changes to your domain's nameservers and unauthorized transfers to other registrars.
Registrar lock (clientTransferProhibited): A registrar-level lock that prevents domain transfers without explicitly removing the lock. Ensure this lock is enabled for all production domains.
Registry lock (serverTransferProhibited): A higher-level lock applied by the domain registry. Changes require verified contact with both the registrar and registry, making unauthorized changes much harder.
4. Secure Your Registrar Account
Your registrar account is the master control for your domain. Essential security measures:
- Strong unique password: Use a password manager to generate and store a long, random password
- Two-factor authentication: Enable 2FA with an authenticator app or hardware security key
- Dedicated email address: Use a separate email address exclusively for your registrar account
5. Implement Email Authentication Records
Email authentication records (SPF, DKIM, DMARC) prevent attackers from spoofing your domain in email. Deploy all three in sequence. See our dedicated SPF/DKIM/DMARC guide for detailed configuration instructions.
6. Audit Your DNS Records Regularly
DNS record sprawl is a common problem — old records pointing to decommissioned services create subdomain takeover vulnerabilities. Regular audits should include:
- Review all CNAME records and verify the target services are still in use
- Check A records and verify the IPs belong to your current hosting infrastructure
- Remove DNS records for services you no longer use
- Check for any records you do not recognize
7. Set Up DNS Change Monitoring
You should be alerted immediately when DNS records for your domain change unexpectedly:
- DNS provider alerts (Cloudflare, AWS Route 53 offer change notifications)
- Third-party monitoring services
- Custom monitoring scripts that check critical records regularly
8. Use Redundant Nameservers
DNS availability depends on your nameservers being reachable. Use at least two nameservers on different networks and in different geographic locations. Consider using secondary DNS with a different provider as a failover.
9. Protect Against Subdomain Takeover
Remove DNS records immediately when deprovisioning any service. Audit all CNAME records regularly and verify target services are still owned by you. Use automated tools to scan for dangling DNS records in your organization.
10. Manage Domain Renewals Proactively
Enable auto-renewal with an active payment method. Set calendar reminders 60 and 30 days before expiration as backup. Use an active email address for your registrar account that you monitor regularly.
Conclusion
DNS security requires attention at multiple layers: securing your registrar account, applying domain locks, enabling DNSSEC, deploying email authentication records, auditing records regularly, and monitoring for unexpected changes. No single control is sufficient, but together these measures make your domain significantly more resilient against common security risks.
Use our free DNS Lookup tool to audit your current DNS configuration, verify email authentication with TXT Record Lookup, and monitor your domain's blacklist status with our Blacklist Checker.
